Authors: S. Mohammadi, A.A. Eftekhar, A. Khelif, W.D. Hunt, A. Adibi
Affilation: Georgia Institute of Technology, United States
Pages: 481 - 484
Keywords: phononic crystals, MEMS, band gap, SOI
We show, by measuring the transmission through a phononic crystal (PC) plate, the evidence of the existence of large phononic band gaps (PBGs) in two-dimensional PCs made by a hexagonal (honeycomb) array of holes etched through a free standing plate of silicon (Si). A CMOS compatible fabrication process is used on a Si on insulator (SOI) substrate to realize the devices. More than 30dB attenuation is observed for eight periods of the hexagonal lattice within the PBG compared to the region outside the PBG, with a very sharp transition. We show that the strong attenuation region matches very well with the theoretical predicted complete PBG. This result opens a new direction in the implementation of practical PC structures with a variety of applications especially in wireless communication devices, and sensing systems.